High power factor constant current output circuit, LED lighting equipment and system

Abstract

The present invention discloses a high power factor constant current output circuit, LED lighting equipment and system, and relates to the technical field of integrated circuits. The high power factor constant current output circuit includes a power factor correction unit and a constant current output unit, which, as the core circuit part in the LED driving circuit, has a high power factor and can output a constant current. The circuit does not use an isolation transformer, but supplies power to the LED through a transformer step-down constant current mode, which can greatly reduce the transmission loss caused by the isolation transformer, and achieve a more efficient electro-optical conversion process under the premise of ensuring electrical safety, and the design is more simplified, which helps to reduce manufacturing costs, improve system reliability, improve the response speed and stability of the lighting system, and achieve a more accurate light control effect.

Description

[0001] This application is a divisional application of the invention patent application filed on October 18, 2023, with the invention name “Non-isolated LED drive circuit, LED lighting equipment and system” and application number 202311345291.3. Technical Field

[0002] The present invention relates to the technical field of integrated circuits, and in particular to a high power factor constant current output circuit, LED lighting equipment and system. Background Art

[0003] In the current market, LED driver circuits play a vital role as a key component of LED lighting systems. However, many LED driver circuits use isolated driver circuit designs. Although the isolation design can ensure electrical safety, due to the characteristics of isolation, this design is often accompanied by a certain degree of energy loss, thereby limiting the energy efficiency of the LED lighting system. Generally speaking, some of the main disadvantages of traditional isolated driver circuit designs are:

[0004] (1) Large energy loss: Traditional isolation drive circuits usually need to convert input electrical energy into high-frequency AC, and then isolate and step down the voltage through a transformer. This conversion process will produce a certain amount of energy loss, thereby reducing the energy efficiency of the entire LED lighting system. Energy waste not only increases energy costs, but also creates an unnecessary burden on the environment.

[0005] (2) Large size and weight: Isolation drive circuits usually need to include isolation components such as transformers, which are large in size and weight. This limits the design flexibility of LED lighting systems, especially in scenarios that require compact space layout or lightweight design, which may cause inconvenience and unnecessary constraints.

[0006] (3) Relatively high cost: The design of traditional isolation drive circuits involves complex isolation components and circuits, which not only increases manufacturing costs but also increases the difficulty of maintenance and repair. This can be a significant cost factor for large-scale commercial and industrial applications.

[0007] (4) Slow response speed: Due to the presence of isolation components and transformers, the response speed of traditional isolated drive circuits is slow. This may limit the performance of the system in scenarios where the LED brightness needs to be adjusted quickly, such as applications that need to respond to environmental changes or light adjustments. Summary of the invention

[0008] In view of this, the embodiments of the present invention provide a high power factor constant current output circuit, an LED lighting device and a system to solve the problems of high energy consumption, high cost and slow response caused by the isolation design of the LED driving circuit in the prior art.

[0009] In the first aspect, an embodiment of the present invention provides a high power factor constant current output circuit, characterized in that the circuit includes: a power factor correction unit and a constant current output unit, wherein the power factor correction unit includes at least a first transformer winding, a first field effect transistor, a second diode and an LED constant current drive controller, and the LED constant current drive controller includes an input voltage sampling pin, an output voltage sampling pin and an analog dimming pin, and controls the working states of the first field effect transistor, the first transformer winding and the second diode in real time through the detection of its input voltage sampling pin and the output voltage sampling pin, thereby achieving a high power factor of the circuit and providing direct current for the constant current output unit; the constant current output unit includes at least a second field effect transistor, a second transformer, a third electrolytic capacitor, a fourth electrolytic capacitor and an operational amplifier, which is used to output a constant current.

[0010] Preferably, the first node serving as the input end of the high power factor constant current output circuit is electrically connected to a rectification and filtering module, and the rectification and filtering module includes at least a first fuse, a first common mode inductor, a second common mode inductor and a rectifier bridge, a first capacitor and a second capacitor, and is used to rectify and filter the AC input and then output a DC signal to the high power factor constant current output circuit.

[0011] Preferably, the LED constant current drive controller includes a zero-crossing and overvoltage detection pin, and the zero-crossing and overvoltage detection pin is electrically connected to the power supply module at a second node, wherein the power supply module includes at least a tenth diode, a fifth electrolytic capacitor and a second winding of a second transformer, for providing a stable DC source for the LED constant current drive controller and the operational amplifier.

[0012] Preferably, the second node is also electrically connected to the temperature detection module, wherein the temperature detection module at least includes an eleventh diode, a twelfth diode, a transistor, the operational amplifier and a sixth electrolytic capacitor, which are used to step down the output of the power supply module and reduce the output power of the output module when overtemperature occurs, wherein the eleventh diode, the sixth electrolytic capacitor and the transistor constitute a voltage stabilizing circuit, which is used to step down the voltage provided by the power supply module; the output end of the operational amplifier is electrically connected to the analog dimming pin of the LED constant current drive controller through the twelfth diode, and when the temperature reaches a predetermined threshold, the operational amplifier controls the twelfth diode to be connected to the LED constant current drive controller, and adjusts the level of the analog dimming pin to achieve power reduction of the output module.

[0013] Preferably, in the power factor correction unit, the input voltage sampling pin of the LED constant current drive controller is electrically connected to the first node via a plurality of series resistors, the first end of the first transformer winding is electrically connected to the first node, the second end of the first transformer winding is electrically connected to the positive electrode of the second diode via a first feedback inductance unit, is electrically connected to the valley detection signal input pin of the LED constant current drive controller via a second resistor and a seventh capacitor, is electrically connected to the drain of the first field effect transistor via a fifth feedback inductance unit, the gate of the first field effect transistor is electrically connected to the gate drive signal pin of the LED constant current drive control via a seventh diode and a fifteenth resistor connected in parallel, the cathode of the second diode is electrically connected to the output voltage sampling pin of the LED constant current drive controller via a plurality of resistors, and the LED constant current drive controller controls the working states of the first field effect transistor, the first transformer winding and the second diode in real time according to the detection of the input voltage sampling pin and the output voltage sampling pin.

[0014] Preferably, in the constant current output unit, the gate of the second field effect tube is electrically connected to the gate drive signal pin of the LED constant current drive controller via an eighth diode and a twentieth resistor in parallel, the drain of the second field effect tube is electrically connected to the first end of the second transformer via a third feedback inductor unit, the second end of the second transformer is electrically connected to the second ends of the third electrolytic capacitor and the fourth electrolytic capacitor in parallel, the first ends of the third electrolytic capacitor and the fourth electrolytic capacitor in parallel are electrically connected to the cathode of the second diode of the power factor correction unit, and the output end of the operational amplifier is electrically connected to the analog dimming pin of the LED constant current drive controller.

[0015] Preferably, in the power supply module, the cathode of the tenth diode is electrically connected to the first end of the forty-ninth resistor, the second end of the forty-ninth resistor is electrically connected to the first end of the fifth electrolytic capacitor and the VCC end, the second end of the fifth electrolytic capacitor and the second end of the second winding of the second transformer are both electrically connected to the signal ground, and the first end of the second winding of the second transformer is electrically connected to the anode of the tenth diode at the second node.

[0016] Preferably, in the temperature detection module, the anode of the eleventh diode is electrically connected to the power supply module at a second node, the cathode of the eleventh diode is electrically connected to the first end of the fiftieth resistor, the second end of the fiftieth resistor is electrically connected to the collector of the transistor, the sixth electrolytic capacitor is electrically connected between the fiftieth resistor and the signal ground, the emitter of the transistor is electrically connected to the positive input terminal of the operational amplifier via the fifty-second resistor, the positive input terminal of the operational amplifier is also electrically connected to the second end of the thermistor, the negative input terminal of the operational amplifier is grounded via the fifty-fourth resistor, and the output terminal of the operational amplifier is electrically connected to the analog dimming pin of the LED constant current drive controller via the twelfth diode.

[0017] In a second aspect, an embodiment of the present invention provides an LED lighting device, wherein the LED lighting device includes the non-isolated LED driving circuit and the LED light source as described in the first aspect.

[0018] In a third aspect, an embodiment of the present invention provides an LED lighting system, which includes the LED lighting device and a controller as described in the second aspect, wherein the controller is at least used to control the switching and brightness of the LED lighting device.

[0019] In summary, the beneficial effects of the present invention are as follows:

[0020] The high power factor constant current output circuit provided by the embodiment of the present invention includes a power factor correction unit and a constant current output unit. As the core circuit part of the non-isolated LED driving circuit, it has a high power factor and a constant current output. The circuit does not use an isolation transformer, but supplies power to the LED through a transformer step-down constant current method. Under the premise of ensuring electrical safety, it can greatly reduce energy loss, thereby achieving a more efficient electro-optical conversion process, and the design is more simplified, reducing many components and complexity required in traditional isolation circuits, which not only helps to reduce manufacturing costs, but also improves the reliability of the system and reduces potential fault points. Due to the simplification of the circuit structure, it can effectively reduce the loss in the energy transmission process, help improve the response speed and stability of the lighting system, can adjust the brightness of the LED more quickly, and achieve a more accurate light control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required for use in the embodiment of the present invention will be briefly introduced below. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work, and these are all within the protection scope of the present invention.

[0022] Figure 11 is a schematic diagram of the structure of a non-isolated LED driving circuit according to an embodiment of the present invention.

[0023] Figure 2 4 is a circuit diagram of a non-isolated LED driving circuit according to an embodiment of the present invention.

[0024] Figure 3 4 is a circuit diagram of a rectifier and filter module according to an embodiment of the present invention.

[0025] Figure 4 is a circuit diagram of an output module according to an embodiment of the present invention.

[0026] Figure 5 is a circuit diagram of a power supply module according to an embodiment of the present invention.

[0027] Figure 6 Schematic diagram of a temperature detection module according to an embodiment of the present invention.

[0028] Figure 7 It is a schematic structural diagram of an LED lighting device according to an embodiment of the present invention.

[0029] Figure 8 Schematic diagram of the structure of the LED lighting system according to the embodiment of the present invention. DETAILED DESCRIPTION

[0030] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0031] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "include..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. The implementation method described below is only schematic, and the division of the module or circuit is only a logical function division, and there may be other division methods when actually implemented. In this embodiment and the accompanying drawings, the elements unrelated to the present invention have been omitted and not illustrated, and the size relationship between the elements in the accompanying drawings is only for easy understanding, not for limiting the actual proportion.

[0032] Embodiment 1

[0033] See also Figure 1 The embodiment of the present invention provides a non-isolated LED driving circuit, the circuit comprising: a rectifying and filtering module 1, an output module 2, a power supply module 3 and a temperature detection module 4, wherein the rectifying and filtering module 1, the power supply module 3 and the temperature detection module 4 are electrically connected to the output module 2 respectively, and the power supply module 3 is electrically connected to the temperature detection module 4. Figure 2The rectifier and filter module 1 at least includes a first fuse F1, a first common mode inductor LF1, a second common mode inductor LF2, a rectifier bridge DB1, a first capacitor C1 and a second capacitor C2, and is used to rectify and filter the alternating current (AC) input, and can convert the alternating current (AC) voltage into a direct current (DC) pulse voltage with a frequency twice that of the AC. The output module 2 includes a power factor correction unit and a constant current output unit, wherein the power factor correction unit at least includes a first transformer winding T1, a first field effect transistor Q1, a second diode D2 and an LED constant current drive controller U1, which is used to enable the circuit to achieve a high power factor and provide direct current for the constant current output unit, and the constant current output unit at least includes a second field effect transistor Q2, a second transformer T2, a third electrolytic capacitor CE3, a fourth electrolytic capacitor CE4 and an operational amplifier U2, which is used to output a constant current; the power supply module 3 at least includes a tenth diode D10, a fifth electrolytic capacitor CE5 and a second winding of the second transformer, which are used to provide a stable direct current source for the LED constant current drive controller U1 and the operational amplifier U2; the temperature detection module 4 at least includes an eleventh diode D11, a twelfth diode D12, a third triode Q3 and the operational amplifier U2, which are used to step down the output of the power supply module 3 and reduce the output power of the output module 2 when overtemperature occurs.

[0034] Preferably, if Figure 3 As shown, in the rectifier and filter module 1, the first end of the first fuse F1 is electrically connected to the power input phase line L, the second end of the first fuse F1 is electrically connected to the third end of the first common mode inductor LF1, the fourth end of the first common mode inductor LF1 is electrically connected to the power input neutral line N, the first end and the second end of the first common mode inductor LF1 are electrically connected to the third end and the fourth end of the second common mode inductor LF2, the first end and the second end of the second common mode inductor LF2 are electrically connected to the second end and the third end of the rectifier bridge, respectively, and the first end of the rectifier bridge is electrically connected to the output module 2 through the RLC parallel circuit composed of the first capacitor C1, the second capacitor C2, the first resistor R1 and the first inductor L1. After the alternating current input from the power input phase line L and the neutral line N passes through the rectifier and filter circuit composed of the first fuse F1, the first common mode inductor LF1, the second common mode inductor LF2 and the rectifier bridge DB1, the first capacitor C1, and the second capacitor C2, the output frequency is a DC pulse voltage twice the original alternating voltage.

[0035] Preferably, the first variable resistor RV1 and the capacitor CX1 are connected in parallel between the first melting point device F1 and the N line to realize filtering and adjustment functions, effectively filter out interference signals, improve the stability and performance of the circuit, and adjust the parameters of the first variable resistor RV1 to meet specific needs. Preferably, a plurality of varistors and variable resistors are connected in series from the power input ground line (PE line) to remove ground interference and electrical interference and improve electrical performance. Preferably, a plurality of resistors are connected between the third end and the fourth end, the first end and the second end of the second common mode inductor LF2 to reduce industrial mode interference and improve signal quality.

[0036] Preferably, in Figure 4 In the power factor correction unit of the output module 2 shown, the LED constant current drive controller U1 uses a BP3368B chip, which includes a high-voltage input pin HV, a floating pin NC, a front-stage Boost valley detection signal input pin ZCD (hereinafter referred to as the valley detection signal input pin or ZCD pin), a front-stage Boost gate drive signal pin GATE1 (hereinafter referred to as the gate drive signal pin), a front-stage Boost current sampling pin CSI, a front-stage Boost power ground pin PGND1, a PWN dimming pin PWN, an input voltage sampling pin INFB, a rear-stage Buck zero-crossing and OVP detection pin FB (hereinafter referred to as the zero-crossing and overvoltage detection pin), a front-stage Boost output voltage sampling pin BFB (hereinafter referred to as the output voltage sampling pin), a front-stage Boost loop compensation pin COMP, an analog dimming pin DIM, a rear-stage Buck power ground and signal ground pin PGND2, a rear-stage Buck MOSFET current sampling pin CS2, a rear-stage Buck MOSFET gate drive signal pin GATE2 (hereinafter referred to as the gate drive signal pin), and a chip working power supply pin VCC. Please refer to the chip product manual for the functional electrical parameters of each pin, which will not be described here.

[0037] Among them, the output node of the rectifier and filter module 1, i.e., the first node 11, is electrically connected to the input voltage sampling pin INFB of the LED constant current drive controller U1 through three series resistors (the tenth resistor R10, the seventeenth resistor R17 and the thirty-first resistor R31), and on the other hand, the first end of the first transformer winding T1 is connected to the first node 11 of the rectifier and filter module 1, and the second end of the first transformer winding T1 is electrically connected to the positive electrode of the second diode D2 through the first feedback inductor unit (including the first feedback inductor FB1 and the second feedback inductor FB2 connected in parallel), and is also electrically connected to the valley detection signal input pin ZCD of the LED constant current drive controller U1 through the second resistor R2 and the seventh capacitor C7. The fifth feedback inductor unit (including the fifth feedback inductor FB5 and the sixth feedback inductor FB6 connected in parallel) is electrically connected to the drain of the first field effect transistor Q1, the gate of the first field effect transistor Q1 is electrically connected to the gate drive signal pin GATE1 of the LED constant current drive controller U1 via the seventh diode D7 and the fifteenth resistor R15 connected in parallel, the cathode of the second diode D2 is electrically connected to the output voltage sampling pin BFB of the LED constant current drive controller U1 via several resistors, and the LED constant current drive controller U1 controls the working states of the first field effect transistor Q1, the first transformer winding T1 and the second diode D2 in real time according to the detection of the input voltage sampling pin INFB and the output voltage sampling pin BFB. In the output module 2, the working states of the first field effect tube Q1, the first transformer T1 and the second diode D2 can be controlled in real time by detecting the INFB pin and the BFB pin in the LED constant current drive controller U1, so that the circuit achieves a high power factor. At the same time, it is filtered into direct current by the second electrolytic capacitor CE2 and provided to a constant current input unit composed of the second field effect tube, the second transformer T2, the third electrolytic capacitor CE3, the fourth electrolytic capacitor CE4 and the operational amplifier U2. Preferably, the model of the operational amplifier is LM321. Both the first field effect tube and the second field effect tube are N-channel enhancement field effect tubes.

[0038] See also Figure 2The output module 2 includes a power factor correction unit and a constant current output unit, wherein the power factor correction unit at least includes a first transformer winding T1, a first field effect transistor Q1, a second diode D2 and an LED constant current drive controller U1, which is used to enable the circuit to achieve a high power factor and provide direct current for the constant current output unit, and the constant current output unit at least includes a second field effect transistor Q2, a second transformer T2, a third electrolytic capacitor CE3, a fourth electrolytic capacitor CE4 and an operational amplifier U2, which is used to output a constant current. In the constant current output unit, the gate of the second field effect transistor Q2 is electrically connected to the gate drive signal pin GATE2 of the LED constant current drive controller U1 via the eighth diode D8 and the twentieth resistor R20 connected in parallel, the drain of the second field effect transistor Q2 is electrically connected to the cathode of the second diode D2 of the power factor correction unit via the third feedback inductor unit (including the fourth feedback inductor FB4 and the third feedback inductor FB5 connected in parallel) and the fifth diode D5 and the sixth diode D6 connected in parallel, the first end of the second transformer T2 is electrically connected to the third feedback inductor unit (including the fourth feedback inductor FB4 and the third feedback inductor FB5 connected in parallel), the second end of the second transformer T2 is electrically connected to the second ends of the third electrolytic capacitor CE3 and the fourth electrolytic capacitor CE4 connected in parallel, the first ends of the third electrolytic capacitor CE3 and the fourth electrolytic capacitor CE4 connected in parallel are electrically connected to the cathode of the second diode D2 of the power factor correction unit, and the output end of the operational amplifier U2 is electrically connected to the analog dimming pin DIM of the LED constant current drive controller U1. The operational amplifier U2 can control the current output to the LED by detecting the loop current of the second field effect tube, and the magnitude of the current is determined by the magnitude of the driving duty cycle given to the second field effect tube by the operational amplifier U2.

[0039] Preferably, see Figure 5, at least the tenth diode D10, the fifth electrolytic capacitor CE5 and the second winding T2B of the second transformer form a power supply module 3 for power rectifier filtering, which provides a stable DC source for the LED constant current drive controller U1 and the operational amplifier U2. In the power supply module 3, the cathode of the tenth diode D10 is electrically connected to the VCC terminal via the forty-ninth resistor R49, the anode of the tenth diode D10 is electrically connected to the first end of the second winding T2B of the second transformer, the second end of the second winding T2B of the second transformer is electrically connected to the second end of the fifth electrolytic capacitor CE5, the first end of the fifth electrolytic capacitor CE5 is electrically connected to the VCC terminal, the second end of the fifth electrolytic capacitor CE5 is electrically connected to the second end of the second winding T2B of the second transformer, the first end of the second winding T2B of the second transformer is electrically connected to the anode of the tenth diode D10 at the second node 31, the second node 31 is electrically connected to the overvoltage detection pin FB of the LED constant current drive controller U1, and the second node 31 is also electrically connected to the temperature detection module 4 to provide a DC source for the operational amplifier U2.

[0040] Preferably, if Figure 6 As shown, in the temperature detection module 4, the positive electrode of the eleventh diode D11 is electrically connected to the second node 31 in the power supply module 3, the negative electrode of the eleventh diode D11 is electrically connected to the first end of the fiftieth resistor R50, the second end of the fiftieth resistor R50 is electrically connected to the collector of the transistor Q3, the sixth electrolytic capacitor CE6 is electrically connected between the second end of the fiftieth resistor and the signal ground GND, the emitter of the transistor is electrically connected to the positive input terminal of the operational amplifier U2 via the fifty-second resistor R52, the positive input terminal of the operational amplifier U2 is electrically connected to the second end of the thermistor RT1, the first end of the thermistor RT1 is electrically connected to the signal ground, the negative input terminal of the operational amplifier is grounded via the fifty-fourth resistor R54, and the output terminal of the operational amplifier U2 is electrically connected to the analog dimming pin DIM of the LED constant current drive controller U1. Among them, the eleventh diode D11, the sixth electrolytic capacitor CE6 and the transistor Q3 form a voltage stabilizing circuit to step down the voltage provided by the power supply module 3; the operational amplifier U2 compares the temperature detected by the thermal resistor RT1. When the temperature reaches the set threshold, the operational amplifier U2 controls the twelfth diode to be connected to the analog dimming pin DIM of the LED constant current drive controller U1. By adjusting the level of the analog dimming pin DIM, the output module 2 controlled by the LED constant current drive controller U1 is reduced in power, thereby realizing the function of reducing the output power due to over-temperature.

[0041] In summary, the non-isolated LED driving circuit of the embodiment of the present invention rectifies and filters the AC input through the rectifying and filtering module 1, corrects the power factor through the output module 2, and realizes constant control of the output current. In addition, the temperature detection module 4 is used to realize the control of power reduction under high temperature, thereby realizing a stable and efficient LED driving circuit. The circuit does not use an isolation transformer, but supplies power to the LED through a transformer step-down constant current method, which can greatly reduce the transmission loss caused by the isolation transformer and achieve high-efficiency output.

[0042] The non-isolated LED driving circuit of this embodiment reduces energy loss as much as possible while ensuring electrical safety, thereby achieving a more efficient electro-optical conversion process, and the design is more simplified, reducing many components and complexity required in traditional isolation circuits, which not only helps to reduce manufacturing costs, but also improves system reliability and reduces potential failure points. Due to the simplification of the circuit structure, the loss in the energy transmission process can be effectively reduced. At the same time, the non-isolated LED driving circuit also helps to improve the response speed and stability of the lighting system, and can adjust the brightness of the LED more quickly to achieve a more accurate light control effect.

[0043] Embodiment 2

[0044] like Figure 7 As shown, the second embodiment of the present invention provides an LED lighting device, which includes the non-isolated LED driving circuit as described in the first embodiment and a load LED light source.

[0045] The non-isolated LED driving circuit includes: a rectifier and filter module 1, an output module 2, a power supply module 3 and a temperature detection module 4, wherein the rectifier and filter module 1, the power supply module 3 and the temperature detection module 4 are electrically connected to the output module 2 respectively, and the power supply module 3 and the temperature detection module 4 are electrically connected, and the rectifier and filter module 1 at least includes a first fuse F1, a first common mode inductor LF1, a second common mode inductor LF2 and a rectifier bridge DB1, a first capacitor C1 and a second capacitor C2, which are used to rectify and filter the AC input; the output module 2 includes a power factor correction unit and a constant current output unit, wherein the power factor correction unit at least includes a first transformer winding T1, a first field effect transistor Q1, a second diode D2 and an LED constant current drive controller U1 , used to enable the circuit to achieve a high power factor and provide direct current for the constant current output unit, the constant current output unit at least includes a second field effect transistor Q2, a second transformer T2, a third electrolytic capacitor CE3, a fourth electrolytic capacitor CE4 and an operational amplifier U2, for outputting a constant current; the power supply module 3 at least includes a tenth diode D10, a fifth electrolytic capacitor CE5 and a second winding of the second transformer, for providing a stable direct current source for the LED constant current drive controller U1 and the operational amplifier U2; the temperature detection module 4 at least includes an eleventh diode D11, a twelfth diode D12, a third transistor Q3 and the operational amplifier U2, for stepping down the output of the power supply module 3 and reducing the output power of the output module 2 when overtemperature occurs.

[0046] The non-isolated LED driver device can reduce energy loss as much as possible while ensuring electrical safety, thereby achieving a more efficient electro-optical conversion process. In addition, the design is simpler, with fewer device components and complexity, which not only helps to reduce manufacturing costs, but also improves device reliability and reduces potential failure points.

[0047] Embodiment 3

[0048] like Figure 8 As shown, the third embodiment of the present invention provides an LED lighting system, the device includes the LED lighting device and a controller as described in the second embodiment, the controller is at least used to control the switch and brightness of the LED device. The LED lighting device at least includes the non-isolated LED driving circuit and LED light source as described in the first embodiment.

[0049] The non-isolated LED driving circuit includes: a rectifier and filter module 1, an output module 2, a power supply module 3 and a temperature detection module 4, wherein the rectifier and filter module 1, the power supply module 3 and the temperature detection module 4 are electrically connected to the output module 2 respectively, and the power supply module 3 and the temperature detection module 4 are electrically connected, and the rectifier and filter module 1 at least includes a first fuse F1, a first common mode inductor LF1, a second common mode inductor LF2 and a rectifier bridge DB1, a first capacitor C1 and a second capacitor C2, which are used to rectify and filter the AC input; the output module 2 includes a power factor correction unit and a constant current output unit, wherein the power factor correction unit at least includes a first transformer winding T1, a first field effect transistor Q1, a second diode D2 and an LED constant current drive controller U1 , used to enable the circuit to achieve a high power factor and provide direct current for the constant current output unit, the constant current output unit at least includes a second field effect transistor Q2, a second transformer T2, a third electrolytic capacitor CE3, a fourth electrolytic capacitor CE4 and an operational amplifier U2, for outputting a constant current; the power supply module 3 at least includes a tenth diode D10, a fifth electrolytic capacitor CE5 and a second winding of the second transformer, for providing a stable direct current source for the LED constant current drive controller U1 and the operational amplifier U2; the temperature detection module 4 at least includes an eleventh diode D11, a twelfth diode D12, a third transistor Q3 and the operational amplifier U2, for stepping down the output of the power supply module 3 and reducing the output power of the output module 2 when overtemperature occurs.

[0050] The LED lighting system can reduce energy loss as much as possible while ensuring electrical safety, thereby achieving a more efficient electro-optical conversion process. In addition, the design is more simplified, reducing the complexity of the entire lighting system, which not only helps to reduce manufacturing costs, but also improves the reliability of the lighting system and reduces potential failure points.

[0051] The non-isolated LED driving circuit provided by the present invention is described in detail above. Those skilled in the art will further understand that the various illustrative logic blocks, modules, circuits and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, various illustrative components, blocks, modules, circuits and steps have been described above in general terms of functionality. Whether the functionality is implemented as hardware or software depends on the specific use and the design constraints imposed on the entire system. Those skilled in the art can implement the described functionality in different ways for each specific use. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly used in other related technical fields, are similarly included in the patent protection scope of the present invention. It should not be understood as a limitation of the present invention.

[0052] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A high power factor constant current output circuit, characterized in that: The circuit includes: a power factor correction unit and a constant current output unit, wherein the power factor correction unit at least includes a first transformer winding, a first field effect tube, a second diode and an LED constant current drive controller, and the LED constant current drive controller includes an input voltage sampling pin, an output voltage sampling pin and an analog dimming pin, and controls the working state of the first field effect tube, the first transformer winding and the second diode in real time through the detection of its input voltage sampling pin and output voltage sampling pin, so as to achieve a high power factor of the circuit and provide direct current for the constant current output unit; the constant current output unit at least includes a second field effect tube, a second transformer, a third electrolytic capacitor, a fourth electrolytic capacitor and an operational amplifier, and is used to output a constant current; wherein, in the power factor correction unit, the input voltage sampling pin of the LED constant current drive controller is connected to the high power source through a plurality of series resistors. The first node of the input end of the factor constant current output circuit is electrically connected, the first end of the first transformer winding is electrically connected to the first node, the second end of the first transformer winding is electrically connected to the positive electrode of the second diode through the first feedback inductor unit, is electrically connected to the valley detection signal input pin of the LED constant current drive controller through the second resistor and the seventh capacitor, and is electrically connected to the drain of the first field effect transistor through the fifth feedback inductor unit, the gate of the first field effect transistor is electrically connected to the gate drive signal pin of the LED constant current drive controller through the seventh diode and the fifteenth resistor connected in parallel, the cathode of the second diode is electrically connected to the output voltage sampling pin of the LED constant current drive controller through a plurality of resistors, and the LED constant current drive controller controls the working states of the first field effect transistor, the first transformer winding and the second diode in real time according to the detection of the input voltage sampling pin and the output voltage sampling pin.

2. The high power factor constant current output circuit according to claim 1, characterized in that: The first node is electrically connected to a rectification and filtering module, which includes at least a first fuse, a first common-mode inductor, a second common-mode inductor and a rectifier bridge, a first capacitor and a second capacitor, and is used to rectify and filter the AC input and then output a DC signal to the high power factor constant current output circuit.

3. The high power factor constant current output circuit according to claim 1, characterized in that: The LED constant current drive controller includes a zero-crossing and overvoltage detection pin, and the zero-crossing and overvoltage detection pin is electrically connected to the power supply module at a second node, wherein the power supply module includes at least a tenth diode, a fifth electrolytic capacitor, and a second winding of a second transformer, for providing a stable DC source for the LED constant current drive controller and the operational amplifier.

4. The high power factor constant current output circuit according to claim 3, characterized in that: The second node is also electrically connected to the temperature detection module, wherein the temperature detection module at least includes an eleventh diode, a twelfth diode, a transistor, the operational amplifier and a sixth electrolytic capacitor, which are used to step down the output of the power supply module and reduce the output power of the output module when overtemperature occurs, wherein the eleventh diode, the sixth electrolytic capacitor and the transistor constitute a voltage stabilizing circuit, which is used to step down the voltage provided by the power supply module; the output end of the operational amplifier is electrically connected to the analog dimming pin of the LED constant current drive controller through the twelfth diode, and when the temperature reaches a predetermined threshold, the operational amplifier controls the twelfth diode to be connected to the LED constant current drive controller, and the power of the output module is reduced by adjusting the level of the analog dimming pin.

5. The high power factor constant current output circuit according to claim 1, characterized in that: In the constant current output unit, the gate of the second field effect tube is electrically connected to the gate drive signal pin of the LED constant current drive controller via an eighth diode and a twentieth resistor in parallel, the drain of the second field effect tube is electrically connected to the first end of the second transformer via a third feedback inductor unit, the second end of the second transformer is electrically connected to the second ends of the third electrolytic capacitor and the fourth electrolytic capacitor in parallel, the first ends of the third electrolytic capacitor and the fourth electrolytic capacitor in parallel are electrically connected to the cathode of the second diode of the power factor correction unit, and the output end of the operational amplifier is electrically connected to the analog dimming pin of the LED constant current drive controller.

6. The high power factor constant current output circuit according to claim 3, characterized in that: In the power supply module, the cathode of the tenth diode is electrically connected to the first end of the forty-ninth resistor, the second end of the forty-ninth resistor is electrically connected to the first end of the fifth electrolytic capacitor and the VCC end, the second end of the fifth electrolytic capacitor and the second end of the second winding of the second transformer are both electrically connected to the signal ground, and the first end of the second winding of the second transformer is electrically connected to the anode of the tenth diode at the second node.

7. The high power factor constant current output circuit according to claim 4, characterized in that: In the temperature detection module, the anode of the eleventh diode is electrically connected to the power supply module at a second node, the cathode of the eleventh diode is electrically connected to the first end of the fiftieth resistor, the second end of the fiftieth resistor is electrically connected to the collector of the transistor, the sixth electrolytic capacitor is electrically connected between the fiftieth resistor and the signal ground, the emitter of the transistor is electrically connected to the positive input terminal of the operational amplifier via the fifty-second resistor, the positive input terminal of the operational amplifier is also electrically connected to the second end of the thermistor, the negative input terminal of the operational amplifier is grounded via the fifty-fourth resistor, and the output terminal of the operational amplifier is electrically connected to the analog dimming pin of the LED constant current drive controller via the twelfth diode.

8. An LED lighting device, characterized in that: The device comprises the high power factor constant current output circuit as claimed in any one of claims 1 to 7 and at least one LED light source.

9. An LED lighting system, characterized in that: The system comprises the LED lighting device and a controller as claimed in claim 8, wherein the controller is used at least to control the switching and brightness of the LED lighting device.

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